Secondary battery

Abstract

The present disclosure relates to a secondary battery. The technical problem to be solved is to provide a secondary battery capable of increasing stability in a cell and preventing an internal short circuit. To this end, the present disclosure provides a secondary battery comprising: an electrode assembly comprising a first electrode plate, a separator, and a second electrode plate; a case accommodating the electrode assembly and having an open bottom portion; a terminal extending through the upper surface portion of the case and coupled to the case through a first gasket; a first current-collecting plate interposed between the upper surface portion of the electrode assembly and the case to electrically connect the first electrode plate to the terminal; and a cap plate sealing the lower bottom of the case, wherein: the first current-collecting plate comprises an electrode plate connection portion connected to the first electrode plate of the electrode assembly, and a terminal connection portion located at the center of the electrode plate connection portion and connected to the terminal; the terminal is coupled to a terminal hole of the case; the terminal includes a fastening portion located inside the case; the fastening portion is coupled to the upper surface of the terminal connection portion; and an insulating member is attached to the first current-collecting plate while avoiding a current-collecting welding area.

Description

secondary batteries

[0001] This disclosure relates to a secondary battery.

[0002] Secondary batteries, unlike non-rechargeable primary batteries, are rechargeable and dischargeable. Low-capacity secondary batteries are used in small, portable electronic devices such as smartphones, feature phones, tablet computers, laptops, digital cameras, and camcorders, while large-capacity secondary batteries are widely used for motor drive and power storage in hybrid and electric vehicles.

[0003] These secondary batteries can be categorized into cylindrical, square, and pouch-shaped types based on their external appearance. Cylindrical secondary batteries typically include an electrode assembly, can, and cap assembly. Furthermore, these secondary batteries require measures to enhance intra-cell stability and prevent internal short circuits.

[0004] The above-described information disclosed in the background technology of this invention is only intended to improve understanding of the background of the present invention, and therefore may include information that does not constitute prior art.

[0005] The present invention provides a secondary battery capable of increasing stability within a cell and preventing internal short circuits.

[0006] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0007] According to one embodiment of the present invention for solving the above technical problem, a secondary battery comprises: an electrode assembly including a first electrode plate, a separator, and a second electrode plate; a case in which the electrode assembly is accommodated and has an open bottom; a terminal penetrating an upper surface of the case and coupled to the case through a first gasket; a first current collector plate interposed between the upper surface of the electrode assembly and the case and electrically connecting the first electrode plate and the terminal; and a cap plate sealing the lower surface of the case, wherein the first current collector plate includes a plate connection portion connected to the first electrode plate of the electrode assembly, and a terminal connection portion located at the center of the plate connection portion and connected to the terminal, the terminal is coupled to a terminal hole of the case, the terminal includes a fastening portion located inside the case, the fastening portion is coupled to an upper surface of the terminal connection portion, and an insulating member can be attached to the first current collector plate while avoiding a current collecting welding area.

[0008] The above first collector plate may further include a fuse portion positioned between the terminal connection portion and the electrode plate connection portion.

[0009] The above fuse portion may include a fuse hole formed along a portion of the outer periphery of the terminal connection portion; and a plate connection portion connecting the terminal connection portion and the plate connection portion.

[0010] The above fuse hole can be formed in a C-shaped shape on a plane.

[0011] The above insulating member can be attached to the lower surface of the fuse portion.

[0012] The diameter of the above insulating member may be equal to or greater than the diameter of the above fuse portion.

[0013] The diameter of the insulating member may be 20% to 40% of the diameter of the electrode assembly.

[0014] The above insulating member may be circular.

[0015] The above insulating member may be square.

[0016] The above insulating member may be an insulating tape, and an adhesive may be attached to both facing edges of the insulating tape.

[0017] The above insulating member may be an insulating tape, and an adhesive may be attached to a portion of the edge of the insulating tape.

[0018] The above insulating member may be an insulating tape, and an adhesive may be attached to the outer side of the insulating tape along the edge of the insulating tape.

[0019] An adhesive may be attached in a circular shape to the outer side of the above insulating tape.

[0020] The above fuse hole may be formed in a circular shape on a plane along the outer periphery of the terminal connection portion.

[0021] The above current collecting welding area can be formed radially in the edge area of ​​the first current collecting plate.

[0022] The above first collector plate is located on the outside of the fuse section and may include a plurality of buffer slits provided symmetrically around the fuse section.

[0023] The above buffer slit may have a U-shape in plan view.

[0024] The above insulating member can be attached to the lower surface of the fuse section while avoiding the current collecting welding area and the buffer slit.

[0025] The above fuse section may include one or more fuse holes, and the fuse holes may be positioned concentrically with respect to the center of the first collector plate.

[0026] The terminal connection portion may protrude in the direction of the electrode assembly and be stepped relative to the electrode plate connection portion.

[0027] The above insulating member may be formed of an insulating tape or by coating a material having insulating properties.

[0028] The above case may be cylindrical.

[0029] According to the present invention, by attaching an insulating member to a current collector plate while avoiding a current collector welding area, stability within the cell can be improved and internal short circuits can be prevented.

[0030] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0031] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0032] Figure 1 is a perspective view of a secondary battery according to an embodiment of the present invention.

[0033] Figure 2 is a cross-sectional view of a secondary battery according to an embodiment of the present invention.

[0034] Figure 3 is an enlarged view of part A of Figure 2.

[0035] FIG. 4 is a drawing showing a first collector plate according to an embodiment of the present invention, an insulating member formed on the first collector plate, and a welding area applied to the first collector plate.

[0036] FIG. 5 is a drawing showing a first collector plate and an insulating member formed on the first collector plate according to another embodiment of the present invention.

[0037] FIG. 6 is a drawing showing the coating form of an adhesive coated on an insulating tape during the manufacturing process of a secondary battery according to an embodiment of the present invention.

[0038] FIG. 7 is a drawing showing the coating form of an adhesive coated on an insulating tape during the manufacturing process of a secondary battery according to another embodiment of the present invention.

[0039] FIG. 8 is a drawing showing the coating form of an adhesive coated on an insulating tape during the manufacturing process of a secondary battery according to another embodiment of the present invention.

[0040] FIG. 9 is a drawing showing the coating form of an adhesive coated on an insulating tape during the manufacturing process of a secondary battery according to another embodiment of the present invention.

[0041] FIG. 10a and FIG. 10b are drawings schematically showing the configuration of a secondary battery pack according to an embodiment of the present invention.

[0042] Figure 11a is a perspective view illustrating an exemplary body.

[0043] FIG. 11b is a drawing for explaining a vehicle including the secondary battery pack of FIG. 10.

[0044] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as substitutes for them at the time of filing this application.

[0045] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0046] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0047] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0048] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0049] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0050] Any configuration being placed "on (or under)" or "above (or below)" a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of said component, but also that other configurations may intervene between said component and any configuration placed on (or below) said component.

[0051] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component. Furthermore, when it is said that a part is electrically coupled to another part, this includes not only cases where they are directly connected, but also cases where they are connected with another element in between.

[0052] When reference is made throughout the specification to "A and / or B," this means A, B, or A and B, unless otherwise stated. In other words, "and / or" includes all or any combination of the listed items. When reference is made to "C through D," this means C or more and D or less, unless otherwise stated.

[0053] The terminology used herein is for the purpose of describing embodiments of the present disclosure and is not intended to be limiting of the present disclosure.

[0054] In exemplary embodiments of cylindrical batteries according to the embodiments of the present disclosure, one of the cylindrical batteries is selected and the selected battery is described as having a general structure, and in the case of a generally applicable technology, the general structure of the cylindrical battery is described.

[0055] FIG. 1 is a perspective view of a secondary battery (10) according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a secondary battery (10) according to an embodiment of the present invention, and FIG. 3 is an enlarged view of part A of FIG. 2.

[0056] Referring to FIGS. 1 to 3, a secondary battery (10) includes an electrode assembly (200), a case (100) that accommodates the electrode assembly (200) and an electrolyte therein, a first current collector (300), a second current collector (400), a terminal (500) provided on one side of the case (100), and a cap plate (600) provided on the other side of the case (100).

[0057] Referring to FIGS. 1 and 2, the case (100) may include a circular upper surface (110) and a cylindrical side surface (130) extending downward from the upper surface (110). In some examples, the lower portion of the side surface (130) may be open, and the case (100) may have a cylindrical shape with an open bottom.

[0058] A terminal hole (111) can be formed through the center of the upper surface (110) of the case (100), and a terminal (500) can be installed in the terminal hole (111).

[0059] The side portion (130) may be formed integrally with the upper portion (110) by being connected to the upper surface portion (110). The lower portion of the side portion (130) may be open, and a cap plate (600) may be coupled to the open end. A beading portion (132) may be formed by contacting the lower portion of the side portion (130). The beading portion (132) may be formed concavely inward from the side portion (130). An end spaced apart from the beading portion (132) may be bent toward the inside of the case (100) to form a crimping portion (134). The detachment of the electrode assembly (200) may be prevented by the beading portion (132). In some examples, a cap plate (600) may be placed between the beading portion (132) and the crimping portion (134). The crimping part (134) can secure the cap plate (600) to seal the case (100).

[0060] The case (100) accommodates an electrode assembly (200) and an electrolyte, and together with a cap plate (600), can form the outer shape of a secondary battery (10). The case (100) can be made of, for example, nickel-plated iron.

[0061] The electrode assembly (200) may include a separator (230), a first electrode plate (210) and a second electrode plate (220) positioned with the separator (230) between them, and may be wound in a jelly-roll shape.

[0062] The first electrode plate (210) includes a first substrate and a first active material layer positioned on the first substrate. A first non-coated portion of the first substrate, where the first active material layer is not positioned, may extend outward, and a plurality of first substrate tabs (214) may be formed by processing the first non-coated portion by notching or the like. In the present embodiment, the first substrate tabs (214) may be positioned toward the upper surface (110) of the case (100). The first electrode plate (210) may be electrically connected to a terminal (500) via a first current collector (300). The first current collector (300) and the first substrate tab (214) may be electrically and mechanically coupled to each other by welding, and the terminal (500) may be electrically and mechanically coupled to the first current collector (300) by welding.

[0063] The second electrode plate (220) may include a second substrate and a second active material layer positioned on the second substrate. A second non-coated portion of the second substrate, where the second active material layer is not positioned, may extend outward, and a plurality of second substrate tabs (224) may be formed by processing the second non-coated portion by notching or the like. In the present embodiment, the second substrate tabs (224) may be positioned toward the lower portion of the case (100). The second electrode plate (220) may be electrically connected to the case (100) via the fourth current collector (400). The second current collector (400) and the second substrate tab (224) may be electrically and mechanically coupled to each other by welding, and the second current collector (400) may be electrically and mechanically coupled to the case (100).

[0064] The first electrode plate (210) can function as an anode. In this case, the first substrate can be composed of, for example, aluminum foil, and the first active material layer can include, for example, a transition metal oxide. The second electrode plate (220) can function as an anode. In this case, the second substrate can be composed of, for example, copper foil or nickel foil, and the second active material layer can include, for example, graphite.

[0065] The separator (230) functions to prevent short circuiting between the first electrode plate (210) and the second electrode plate (220) while allowing the movement of lithium ions. The separator (230) may be composed of, for example, a polyethylene film, a polypropylene film, a polyethylene-polypropylene film, etc.

[0066] The first collector plate (300) may have a circular shape and may be made of the same material as the first electrode plate (210). The first collector plate (300) may be welded with its lower surface in contact with the first substrate tab (214). In addition, the upper surface of the first collector plate (300) may be welded with a terminal (500) in the form of a rivet. Accordingly, the first collector plate (300) and the terminal (500) may be electrically connected, and consequently, the first electrode plate (210) and the terminal (500) may be electrically connected by the first collector plate (300).

[0067] The second collector plate (400) may be made of the same material as the second electrode plate (220). The second collector plate (400) may include a plate-shaped surface portion (410) and a contact portion (420) extending from the plate portion (410). The upper surface of the plate portion (410) may be welded while in contact with the second substrate tab (224). Accordingly, the second collector plate (400) and the second electrode plate (220) may be electrically connected. The contact portion (420) may extend downward from the edge of the plate portion (410) and may be in close contact with the inner surface of the beading portion (132). The contact portion (420) may be welded to the beading portion (312) to be electrically connected.

[0068] The cap plate (600) may include a flat portion (612) in the shape of a disk, an inclined surface (614) connected to the flat portion (612), and an extended surface (616) connected to the inclined surface (614). The flat portion (612) may be arranged approximately parallel to the second collector plate (400). The inclined surface (614) may extend downwardly from an edge of the flat portion (612) in an inclined direction. The extended surface (616) may extend from an edge of the inclined surface (614) and be parallel to the flat portion (612). The extended surface (616) may be arranged between the beading portion (132) and the crimping portion (134) while being surrounded by a gasket (620). A notch (612a) may be formed on the flat portion (612). The notch (612a) may be ruptured when the pressure inside the secondary battery (10) exceeds a certain pressure. Gas inside the secondary battery (10) may be discharged due to the rupture of the notch (612a). In other words, the notch (612a) functions as a vent.

[0069] The gasket (620) can insulate between the case (100) and the cap plate (600). The gasket (620) is placed between the lower portion of the beading portion (132) and the crimping portion (134), and can surround the extension surface (616) of the cap plate (600). The gasket (620) can surround part or all of the extension surface (616). The side where the gasket (620) and the extension surface (616) come into contact can be defined as the inner side, and the side where the gasket (620) comes into contact with the beading portion (132) can be defined as the outer side. At this time, a part of the contact portion (420) of the second collector plate (400) can be inserted between the outer upper portion of the gasket (620) and the beading portion (132). Therefore, the contact portion (420) of the second collector plate (400) and the extended surface (616) of the cap plate (610) do not come into contact with each other due to the gasket (620). That is, the gasket (620) can mutually insulate the cap plate (600) and the case (100), and mutually insulate the cap plate (600) and the second collector plate (400). The gasket (620) can be formed of a resin material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc.

[0070] The terminal (500) can penetrate the upper surface (110) of the case (100) and be coupled to the case (100) through the gasket (530). A terminal hole (111) is formed in the central area of ​​the upper surface (110) of the case (100), and the terminal (500) can be installed in the terminal hole (111). The terminal (500) can be installed by riveting. The terminal (500) can include a shank (501) that is disposed to penetrate the terminal hole (111), a head (502) that is provided on one end of the shank (501) and is formed to be larger than the terminal hole (111) and is supported on the outer surface of the case (100), and a fastening portion (503) that is deformed to be larger than the terminal hole (111) on the other end of the shank (501) and is supported on the inner surface of the case (100). The fastening portion (503) may have a bucktail shape and is located inside the case (100). The fastening portion (503) may contact the first collector plate (300) and be welded, thereby forming an electrical and mechanical connection between the terminal (500) and the first collector plate (300). When the first electrode plate (210) of the electrode assembly (200) is a positive electrode, the terminal (500) may function as a positive terminal.

[0071] In some examples, a gasket (530) may be interposed between the terminal (500) and the case (100) to form a seal and electrical insulation between the terminal (500) and the case (100). The gasket (530) may be formed of a resin material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or the like.

[0072] By the structure described above, the terminal (500) has positive polarity and the case (100) has negative polarity.

[0073] FIG. 4 is a drawing showing a first collector plate according to an embodiment of the present invention, an insulating tape attached to the first collector plate, and a welding area applied to the first collector plate.

[0074] Referring to FIGS. 3 and 4, the first collector plate (300) may include a plate connection portion (310) connected to the first electrode plate (210), a terminal connection portion (320) located at the center of the plate connection portion (310) and in contact with a terminal (500), and a fuse portion (330) located between the terminal connection portion (320) and the plate connection portion (310).

[0075] Referring to Fig. 3, the terminal connection portion (320) protrudes in the direction of the electrode assembly (200) and forms a step with the electrode plate connection portion (310). The first substrate tab (214) of the first electrode plate (210) is coupled to the lower surface of the electrode plate connection portion (310), and the fastening portion (503) of the terminal (500) described above can be coupled to the upper surface of the terminal connection portion (320).

[0076] The fuse part (330) may include a fuse hole (331) formed along a portion of the outer periphery of the terminal connection part (320), and a plate connection part (332) connecting the terminal connection part (320) and the plate connection part (310). The fuse hole (331) may be formed in a circular shape on a plane along the outer periphery of the terminal connection part (320). Referring to FIG. 4, the fuse hole (331) may be formed in a C-shaped shape on a plane. Although FIG. 4 illustrates a case where one fuse hole (331) is formed, a plurality of fuse holes may be formed, and the fuse holes may be positioned concentrically with respect to the center of the first current collector plate (300).

[0077] In some examples, an insulating member (700) may be formed on the first collector plate (300). In FIG. 4, the insulating member (700) formed on the lower surface of the first collector plate (300) is illustrated with a dotted line. The insulating member (700) may be formed on the first collector plate (300) while avoiding the welding zone between the first collector plate (300) and the first electrode plate (210), i.e., the collector welding zone (W). For example, the collector welding zone (W) may be formed radially in an edge region of the first collector plate (300), and the insulating member (700) may be formed in an region surrounded by a plurality of collector welding zones (W).

[0078] Referring to FIG. 3, an insulating member (700) is formed on the lower surface of the fuse portion (330), and the diameter of the insulating member (700) may be equal to or greater than the diameter of the fuse portion (330). The diameter of the insulating member (700) may be 20% to 40% of the diameter of the electrode assembly (200).

[0079] The insulating member (700) may be formed by attaching an insulating tape having insulating properties or by coating a material having insulating properties such as polyimide (PI).

[0080] FIG. 5 is a drawing showing a first collector plate and an insulating tape attached to the first collector plate according to another embodiment of the present invention.

[0081] Referring to FIG. 5, the first current collector plate (800) may include a plurality of buffer slits (340) positioned on the outside of the fuse portion (330). The plurality of buffer slits (340) may be arranged symmetrically with respect to the fuse portion (330). The buffer slits (340) may have a U-shape in plan view. The insulating member (700) may be formed on the lower surface of the fuse portion (330) while avoiding the current collector welding area and the buffer slits (340).

[0082] FIGS. 6 to 8 are drawings showing the coating form of an adhesive coated for attachment of an insulating tape when the insulating member (700) described above is formed by attachment of an insulating tape.

[0083] Referring to Fig. 6, the insulating tape (711) is circular, and an adhesive (713) can be attached to a portion of both facing edges of the insulating tape (711). At this time, the insulating tape (711) has a through hole (712) in the center, and the adhesive (713) is not attached to the through hole (712).

[0084] Referring to Fig. 7, the insulating tape (721) is square, and an adhesive (723) is attached to a portion of both facing edges of the insulating tape (721). At this time, the insulating tape (721) has a through hole (722) in the center, and the adhesive (723) is not attached to the through hole (722).

[0085] Referring to Fig. 8, the insulating tape (731) is square, and an adhesive (733) is attached to opposite edges of the insulating tape (731). At this time, the insulating tape (731) has a through hole (732) in the center, and the adhesive (733) is not attached to the through hole (732).

[0086] Referring to FIG. 9, the insulating tape (741) is circular, and an adhesive (743) may be attached along the edge of the insulating tape (741). In some examples, the adhesive (743) may be attached in a circular shape to the outer side of the insulating tape (741). In this case, the insulating tape (741) has a through hole (742) at the center, and the adhesive (743) is not attached to the through hole (742).

[0087] FIGS. 6 to 9 illustrate examples of cases in which adhesives (713, 723, 733, 743) are formed on multiple insulating tapes (711, 721, 731, 741). After forming the adhesives (713, 723, 733, 743), each insulating tape (711, 721, 731, 741) can be cut and used.

[0088] Meanwhile, in some examples, a compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) may be used as the cathode active material. Specifically, one or more of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used.

[0089] The above composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxide, lithium cobalt-based oxide, lithium manganese-based oxide, lithium iron phosphate-based compound, cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0090] As an example, a compound represented by any one of the following chemical formulas may be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α Dα (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3(0≤f≤2); Li a FePO4(0.90≤a≤1.8).

[0091] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; L 1 is Mn, Al or a combination thereof.

[0092] A positive electrode for a lithium secondary battery may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer includes a positive electrode active material and may further include a binder and / or a conductive material.

[0093] The content of the positive electrode active material may be 90 wt% to 99.5 wt% with respect to 100 wt% of the positive electrode active material layer, and the contents of the binder and conductive material may be 0.5 wt% to 5 wt%, respectively, with respect to 100 wt% of the positive electrode active material layer.

[0094] Al may be used as the above current collector, but is not limited thereto.

[0095] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0096] The material capable of reversibly intercalating / deintercalating the lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0097] As the material capable of doping and dedoping the lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used. The Si-based negative electrode active material is silicon, a silicon-carbon composite, SiO x (0 < x < 2), Si-based alloys or combinations thereof.

[0098] The above silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0099] The silicon-carbon composite may further comprise crystalline carbon. For example, the silicon-carbon composite may comprise a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer positioned on the surface of the core.

[0100] A negative electrode for a lithium secondary battery includes a current collector and a negative electrode active material layer positioned on the current collector. The negative electrode active material layer includes a negative electrode active material and may further include a binder and / or a conductive material.

[0101] For example, the negative electrode active material layer may include 90 to 99 wt% of the negative electrode active material, 0.5 to 5 wt% of the binder, and 0 to 5 wt% of the conductive material.

[0102] The above binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0103] The negative electrode current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof.

[0104] An electrolyte for a lithium secondary battery contains a non-aqueous organic solvent and a lithium salt.

[0105] The above non-aqueous organic solvent acts as a medium through which ions involved in the electrochemical reaction of the battery can move.

[0106] The above non-aqueous organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, an aprotic solvent, or a combination thereof, and may be used alone or in combination of two or more thereof.

[0107] Additionally, when using a carbonate solvent, a mixture of cyclic carbonate and chain carbonate can be used.

[0108] Depending on the type of lithium secondary battery, a separator may be present between the positive and negative electrodes. Such separators may be polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film comprising two or more layers of these.

[0109] The above separator may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof, positioned on one or both sides of the porous substrate.

[0110] The organic material may include a polyvinylidene fluoride polymer or a (meth)acrylic polymer.

[0111] The above inorganic materials are Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include inorganic particles selected from, but not limited to, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0112] The organic and inorganic substances may be mixed and present in one coating layer, or a coating layer including an organic substance and a coating layer including an inorganic substance may be present in a laminated form.

[0113] The secondary battery (10) according to the above-described embodiment can be used to manufacture a secondary battery pack (30). FIGS. 10a and 10b are drawings schematically showing the configuration of a secondary battery pack (30) according to an embodiment of the present invention.

[0114] Referring to FIGS. 10A and 10B, the secondary battery pack (30) may include a plurality of secondary battery modules (20) and a housing (31) for accommodating the plurality of secondary battery modules (20). For example, the housing (31) may include first and second housings (31-1, 31-2) that are coupled in a direction facing each other with the plurality of secondary battery modules (20) interposed therebetween. The plurality of secondary battery modules (20) may be electrically connected to each other using a bus bar (25), and the plurality of secondary battery modules (20) may be electrically connected to each other in a series / parallel or series-parallel mixed manner to obtain a required electrical output. In the drawing, for the convenience of illustration, components such as a bus bar, a cooling unit, and an external terminal for electrically connecting the secondary batteries (batteries) are omitted.

[0115] The secondary battery pack (30) can be mounted on a vehicle (50). The vehicle (50) may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle includes a four-wheeled vehicle or a two-wheeled vehicle.

[0116] Fig. 11a is a perspective view illustrating an exemplary vehicle body (40). Fig. 11b is a drawing for explaining a vehicle (50) including the secondary battery pack (30) of Fig. 10. In Fig. 11a, the secondary battery pack (30) may include a secondary battery pack cover (31-1) (which may correspond to the first housing) which is a part of a vehicle underbody (41) and a pack frame (31-2) (which may correspond to the second housing) which is disposed at a lower portion of the vehicle underbody (41). The secondary battery pack cover (31-1) and the pack frame (31-2) may be formed integrally with the vehicle floor (42). The vehicle underbody (41) separates the inside and the outside of the vehicle, and the pack frame (12) may be disposed at the outside of the vehicle.

[0117] Referring to FIG. 11b, the vehicle (50) may be formed by combining additional components such as a hood (51) at the front of the vehicle and fenders (52) positioned at the front and rear of the vehicle, respectively, with the vehicle body (40). The vehicle (50) includes a secondary battery pack (30) including a secondary battery pack cover (31-1) and a pack frame (31-2), and the secondary battery pack (30) may be combined with the vehicle body (40). That is, the vehicle operates by receiving power from the secondary battery pack (30) according to one embodiment of the present invention.

[0118] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

Claims

1. An electrode assembly including a first electrode plate, a separator, and a second electrode plate; A case in which the electrode assembly is accommodated and the lower part is open; A terminal penetrating the upper surface of the case and coupled to the case through the first gasket; A first current collector plate interposed between the upper surface of the electrode assembly and the case, electrically connecting the first electrode plate and the terminal; and Including a cap plate that seals the lower part of the case, The first collector plate includes a plate connection portion connected to the first electrode plate of the electrode assembly, and a terminal connection portion located at the center of the plate connection portion and connected to the terminal. The above terminal is connected to the terminal hole of the above case, The terminal includes a fastening portion located inside the case, and the fastening portion is coupled to the upper surface of the terminal connection portion. A secondary battery having an insulating member attached thereto, avoiding the current collecting welding area of ​​the first current collecting plate.

2. In paragraph 1, A secondary battery wherein the first collector plate further includes a fuse portion positioned between the terminal connection portion and the electrode plate connection portion.

3. In paragraph 2, The above fuse portion comprises a fuse hole formed along a portion of the outer periphery of the terminal connection portion; and A secondary battery including a plate connecting portion connecting the terminal connecting portion and the plate connecting portion.

4. In paragraph 3, The above fuse hole is a secondary battery formed in a C-shaped shape on a plane.

5. In paragraph 2, The above insulating member is a secondary battery attached to the lower surface of the fuse section.

6. In paragraph 5, A secondary battery in which the diameter of the insulating member is equal to or greater than the diameter of the fuse portion.

7. In paragraph 5, A secondary battery wherein the diameter of the insulating member is 20% to 40% of the diameter of the electrode assembly.

8. In paragraph 1, The above insulating member is a circular secondary battery.

9. In paragraph 1, The above insulating member is a square secondary battery.

10. In paragraph 1, The above insulating material is an insulating tape, A secondary battery having an adhesive attached to the opposite edges of the insulating tape.

11. In paragraph 1, The above insulating material is an insulating tape, A secondary battery having an adhesive attached to a portion of the edge of the above insulating tape.

12. In paragraph 1, The above insulating material is an insulating tape, A secondary battery having an adhesive attached along the edge of the insulating tape on the outer side of the insulating tape.

13. In paragraph 1, A secondary battery having an adhesive attached in a circular shape to the outside of the above insulating tape.

14. In paragraph 3, The above fuse hole is a secondary battery formed in a circular plane along the outer periphery of the terminal connection portion.

15. In paragraph 1, The above-mentioned current collecting welding area is a secondary battery formed radially in the edge area of ​​the first current collecting plate.

16. In paragraph 2, A secondary battery in which the first collector plate is located on the outside of the fuse section and includes a plurality of buffer slits symmetrically provided around the fuse section.

17. In paragraph 16, The above buffer slit is a secondary battery having a U-shape on a plane.

18. In paragraph 16, The above insulating member is a secondary battery attached to the lower surface of the fuse section, avoiding the current collecting welding area and the buffer slit.

19. In paragraph 2, The above fuse section includes one or more fuse holes, The above fuse hole is a secondary battery located concentrically with the center of the first collector plate.

20. In paragraph 1, The terminal connection portion protrudes in the direction of the electrode assembly and is a secondary battery with a step difference from the electrode plate connection portion.

21. In paragraph 1, A secondary battery in which the above insulating member is formed by an insulating tape or by a coating of a material having insulating properties.

22. In paragraph 1, The above case is a cylindrical secondary battery.

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